Historically, CO2 capture processes within power plants have required a significant amount of energy, which reduces the net power output of the power plant. For example, the output of a 500 MW (net) coal-fired power plant may be reduced to about 400 MW (net) after CO2 capture—a 20% energy penalty. To be commercially viable, this energy penalty needs to be reduced substantially. Therefore, new and improved methods for CO2 capture are required to generate electricity efficiently from coal-fired power plants with reduced energy penalties.
Ammonia-based CO2 capture has been considered as the best alternative to conventional amine process, which is very costly. There are several ammonia-based technologies currently under development. Some major challenges of these processes are (1) high energy intensive chilling requirement for flue gas cooling for absorber operation at temperatures<10° C., and (2) large water usage and energy intensive sour stripping for ammonia emission reduction.
Relevant art: US 2012/0129246.